LeetCode Interview Preparation Guide
1. Understand the Interview Format
- Typical Structure: 1-2 coding problems (45-60 minutes)
- Focus Areas: Data structures, algorithms, system design (for senior roles)
- Common Question Types: Arrays, Strings, Linked Lists, Trees, Graphs, DP
2. Learn/Refresh Fundamentals
Essential Data Structures
- Arrays, Strings, Hash Tables
- Linked Lists, Stacks, Queues
- Trees (Binary Trees, BST, Tries)
- Graphs (DFS, BFS, Dijkstra)
- Heaps, Priority Queues
Key Algorithms
- Sorting (QuickSort, MergeSort)
- Searching (Binary Search)
- Recursion & Backtracking
- Dynamic Programming
- Sliding Window, Two Pointers
- Greedy Algorithms
- Bit Manipulation
Resources:
- GeeksforGeeks Data Structures
- FreeCodeCamp Algorithms Course (YouTube)
- Book: "Cracking the Coding Interview" by Gayle Laakmann McDowell
3. Practice Strategically
- Start with Easy problems to build confidence
- Focus on Medium problems (most interview questions)
- Attempt Hard problems for top-tier companies
- Follow topic-wise approach (e.g., "Binary Trees" for a week)
Curated Problem Lists:
4. Master Problem-Solving Techniques
Key Patterns to Recognize:
- Sliding Window
- Two Pointers
- Fast & Slow Pointers
- BFS/DFS
- Topological Sort
- Dynamic Programming (Memoization, Tabulation)
- Backtracking
Tip: Always explain your thought process out loud during practice, as you would in an interview.
5. Mock Interviews & Timing
- Solve problems under time constraints (30-45 mins)
- Practice whiteboarding or online coding environments
Mock Interview Platforms:
- Pramp (Free peer-to-peer mocks)
- Interviewing.io (Paid mocks with real interviewers)
- LeetCode's mock interview feature
6. System Design (For Mid/Senior Roles)
- Study scalability, databases, caching, load balancing
- Practice designing systems like Twitter, TinyURL, etc.
Resources:
- Grokking the System Design Interview
- Book: "Designing Data-Intensive Applications" by Martin Kleppmann
- System Design Primer (GitHub)
7. Behavioral Preparation
- Use the STAR Method (Situation, Task, Action, Result)
- Prepare stories for common questions
Resources:
- Guide to STAR Method
- Book: "Cracking the PM Interview" (useful even for dev roles)
8-Week Study Plan
| Week | Focus Area | Recommended Problems |
|---|---|---|
| 1-2 | Arrays, Strings, Two Pointers | Two Sum, Valid Palindrome, Container With Most Water |
| 3-4 | Linked Lists, Stacks, Queues | Reverse Linked List, Valid Parentheses, Implement Queue using Stacks |
| 5-6 | Trees, Graphs (DFS/BFS) | Invert Binary Tree, Course Schedule, Number of Islands |
| 7-8 | Dynamic Programming, Backtracking | Climbing Stairs, Combination Sum, Word Break |
Consistency Tip: Aim for 15-20 quality problems per week with thorough understanding rather than rushing through many.
Final Tips
- Focus on understanding patterns rather than memorizing solutions
- Revisit mistakes and edge cases regularly
- Prioritize sleep and health - burnout hurts performance
- In interviews: think aloud, ask clarifying questions, and communicate your approach
Good luck with your interview preparation! Remember: consistent, focused practice leads to success.